Cutting tools used to shape a surface of a work piece in milling, turning or grooving operations may comprise a replaceable cutting insert that is mounted at an end of a relatively long, rod-like tool body or insert holder. The tool body has a cutting portion having an insert pocket for mounting the cutting insert therein and a shank at an end opposite to the cutting portion for securing the cutting tool in a tool holder of a machine tool.
In a face-shaping or face-grooving operations, a surface at an end of the work piece that is usually substantially perpendicular to the axis about which the work piece rotates is, respectively, shaped and/or formed with a groove. The surface being shaped or grooved may be an internal surface, relatively deep inside the work piece and a groove being formed in a surface may be a relatively deep groove. For such operations, the cutting tool and insert must be appropriately shaped so that the insert can be inserted into the work piece to a sufficient depth to reach the surface being shaped or the groove being formed. Whereas the cutting tool and insert must have substantial reach, it is generally advantageous that they be sufficiently robust so that in use they are not subject to excessive vibration that prevents them from shaping surfaces of acceptable quality.
However, providing a cutting tool with relatively large reach needed for shaping or grooving an internal surface may affect the robustness of the tool. The cutting tool and/or insert must often be shaped relatively long but having a relatively small cross section. In addition, surfaces of the cutting tool that are close to a curved surface being worked must generally be curved so that they do not contact and interfere with the surface. As a result, it may be difficult for the cutting tool to provide robust mechanical support for the cutting insert near the cutting tool's cutting edge.
To meet design constraints of cutting tools used for face-shaping or face-grooving, the cutting insert retained in these tools may be mounted therein using an adapter. The adapter may be shaped to be mounted on an end of the tool body and may be configured to receive the cutting insert in a suitable insert pocket formed in the adapter. The adapter may be configured with various component support structures for stabilizing the cutting tool and reducing its tendency to vibrate during use and may comprise means for clamping the cutting insert in the pocket. The adaptor may also include means for adjusting the position of the cutting insert in the pocket. Typically, various configurations of bolts are used to secure the components of the adapter to the tool body and to provide the clamping and adjustment functions.
U.S. Pat. No. 5,159,863 describes “an adjustable face-grooving tool holder for holding a cutting insert for cutting circular face grooves having widely differing diameters”. The holding tool comprises a “blade unit” to which a cutting insert is mounted and a “clamping arm” that is mounted on the blade unit using a screw that is tightened to clamp the cutting insert to the blade unit. The blade unit is mounted to the tool body using another screw.
U.S. Pat. No. 5,709,508 describes a cutting tool assembly having an adaptor that is mounted to a tool block using a pair of bolts.
U.S. Pat. No. 6,244,789 describes a cutting tool for cutting the walls of small deep holes. The tool comprises a cutting insert secured to a holder, or tool body. The cutting insert has a “stick-shaped” cutting portion that extends away from a planar plate-like base. The cutting portion has a cutting edge at a far end from the base. Near the center of the base is a bolt through hole which is aligned with a tapped hole in the holder. The cutting insert is secured to the holder by bolting the base into an insert pocket in the holder using a fixing bolt which is inserted through the bolt through hole and screwed into the tapped hole. The pocket has a seating surface on which a planar surface of the plate-like base rests and three projections that extend from peripheral surfaces of the pocket to contact a peripheral side surface of the base along three regions of the base peripheral surface. The cutting insert is clamped at four points. In addition to the three-point contact by the three projections, the insert is also clamped by a set bolt which is fitted through a tapped hole to make contact with the base peripheral side surface. When the set bolt in the tool body is screwed down to contact a fourth region of the base peripheral side surface, the insert “is locked at four points by the three projections . . . and the set bolt”.